Similar to radiant skin in humans, plants also glow when they’re well. A European Space Agency (ESA) satellite could use fluorescence to track the health and productivity of vegetation worldwide.
The Florescence Explorer (FLEX) is a candidate for the European Space Agency’s eighth Earth Explorer mission. The satellite could provide global maps of vegetation fluorescence, which can be used to work out actual photosynthetic activity. This information would improve our understanding of the way carbon moves between plants and the atmosphere and how it affects the carbon and water cycles.
In addition, by offering new information that can be used to improve the management of water and fertilizers, FLEX could also improve agricultural productivity. After the chlorophyll in a plant has absorbed sunlight, the core of the photosynthetic machinery gives off a red glow, or fluorescence. This reflects how efficiently the plant is photosynthesizing, or how well it is “breathing,” and, therefore, how healthy it is.
Measuring plant fluorescence is a challenge. As with most new satellite technology, a concept first has to be tested from an aircraft to demonstrate that it works before anyone thinks of building and launching an instrument into space.
Until recently, an airborne sensor wasn’t available to map the fluorescence over large areas. In fact, for years it was a challenge to detect this relatively small glow outside of the laboratory and over agricultural fields and forests.
But Germany’s Forschungszentrum Jülich research center and Finland’s Specim company now have developed and thoroughly tested the novel Hyplant airborne sensor. As part of the campaign, the sensor has mapped different types of vegetation all over Europe and parts of the United States.
Image courtesy of U. Rascher, Forschungszentrum Jülich.